In order to study the one-shot welding of multiple brazing seams in different parts of the injector,an experimental study on the vacuum brazing process of the injector by using BNi-2 solder was carried out.The effects of surface cleaness, brazing temperature and brazing gap on the sealing performance of the injector were analyzed.The results show that the gaps between brazing seams have an important influence on the sealing performance of the brazed joints of the injection body composed of high temperature alloy and stainless steel.A reasonable brazing seam assembly gap is 10 to 15 μm,and this gap makes the filling rate of the brazing seam more than 90%,and obtains a joint with excellent internal and external quality and sealing property is obtained.